com.uber.cadence.internal.replay

Interface DecisionContext

All Superinterfaces:

ReplayAware

public interface DecisionContext
extends ReplayAware

Represents the context for decider. Should only be used within the scope of workflow definition code, meaning any code which is not part of activity implementations.

Method Summary

Modifier and Type	Method and Description
void	continueAsNewOnCompletion(ContinueAsNewWorkflowExecutionParameters parameters)
java.util.function.Consumer<java.lang.Exception>	createTimer(long delaySeconds, java.util.function.Consumer<java.lang.Exception> callback) Create a Value that becomes ready after the specified delay.
long	currentTimeMillis()
ContinueAsNewWorkflowExecutionParameters	getContinueAsNewOnCompletion()
java.time.Duration	getDecisionTaskTimeout()
java.lang.String	getDomain()
boolean	getEnableLoggingInReplay()
java.time.Duration	getExecutionStartToCloseTimeout()
int	getExecutionStartToCloseTimeoutSeconds()
com.uber.m3.tally.Scope	getMetricsScope()
java.lang.String	getRunId()
java.lang.String	getTaskList()
int	getVersion(java.lang.String changeID, DataConverter dataConverter, int minSupported, int maxSupported) GetVersion is used to safely perform backwards incompatible changes to workflow definitions.
WorkflowExecution	getWorkflowExecution()
java.lang.String	getWorkflowId()
WorkflowType	getWorkflowType()
boolean	isCancelRequested()
java.util.Optional<byte[]>	mutableSideEffect(java.lang.String id, DataConverter dataConverter, Functions.Func1<java.util.Optional<byte[]>,java.util.Optional<byte[]>> func)
java.util.Random	newRandom()
java.util.UUID	randomUUID()
Promise<java.lang.Void>	requestCancelWorkflowExecution(WorkflowExecution execution)
java.util.function.Consumer<java.lang.Exception>	scheduleActivityTask(ExecuteActivityParameters parameters, java.util.function.BiConsumer<byte[],java.lang.Exception> callback) Used to dynamically schedule an activity for execution
void	setContinueAsNewOnCompletion(ContinueAsNewWorkflowExecutionParameters continueParameters)
byte[]	sideEffect(Functions.Func<byte[]> func) Executes the provided function once, records its result into the workflow history.
java.util.function.Consumer<java.lang.Exception>	signalWorkflowExecution(SignalExternalWorkflowParameters signalParameters, java.util.function.BiConsumer<java.lang.Void,java.lang.Exception> callback)
java.util.function.Consumer<java.lang.Exception>	startChildWorkflow(StartChildWorkflowExecutionParameters parameters, java.util.function.Consumer<WorkflowExecution> executionCallback, java.util.function.BiConsumer<byte[],java.lang.Exception> callback) Start child workflow.

Methods inherited from interface com.uber.cadence.internal.replay.ReplayAware

isReplaying

Method Detail

getWorkflowExecution

WorkflowExecution getWorkflowExecution()

getWorkflowType

WorkflowType getWorkflowType()

isCancelRequested

boolean isCancelRequested()

getContinueAsNewOnCompletion

ContinueAsNewWorkflowExecutionParameters getContinueAsNewOnCompletion()

setContinueAsNewOnCompletion

void setContinueAsNewOnCompletion(ContinueAsNewWorkflowExecutionParameters continueParameters)

getExecutionStartToCloseTimeoutSeconds

int getExecutionStartToCloseTimeoutSeconds()

getTaskList

java.lang.String getTaskList()

getDomain

java.lang.String getDomain()

getWorkflowId

java.lang.String getWorkflowId()

getRunId

java.lang.String getRunId()

getExecutionStartToCloseTimeout

java.time.Duration getExecutionStartToCloseTimeout()

getDecisionTaskTimeout

java.time.Duration getDecisionTaskTimeout()

scheduleActivityTask

java.util.function.Consumer<java.lang.Exception> scheduleActivityTask(ExecuteActivityParameters parameters,
                                                                      java.util.function.BiConsumer<byte[],java.lang.Exception> callback)

Used to dynamically schedule an activity for execution

Parameters:

parameters - An object which encapsulates all the information required to schedule an activity for execution

callback - Callback that is called upon activity completion or failure.

Returns:

cancellation handle. Invoke Consumer.accept(Object) to cancel activity task.

startChildWorkflow

java.util.function.Consumer<java.lang.Exception> startChildWorkflow(StartChildWorkflowExecutionParameters parameters,
                                                                    java.util.function.Consumer<WorkflowExecution> executionCallback,
                                                                    java.util.function.BiConsumer<byte[],java.lang.Exception> callback)

Start child workflow.

Parameters:

parameters - An object which encapsulates all the information required to schedule a child workflow for execution

callback - Callback that is called upon child workflow completion or failure.

Returns:

cancellation handle. Invoke Consumer.accept(Object) to cancel activity task.

signalWorkflowExecution

java.util.function.Consumer<java.lang.Exception> signalWorkflowExecution(SignalExternalWorkflowParameters signalParameters,
                                                                         java.util.function.BiConsumer<java.lang.Void,java.lang.Exception> callback)

requestCancelWorkflowExecution

Promise<java.lang.Void> requestCancelWorkflowExecution(WorkflowExecution execution)

continueAsNewOnCompletion

void continueAsNewOnCompletion(ContinueAsNewWorkflowExecutionParameters parameters)

mutableSideEffect

java.util.Optional<byte[]> mutableSideEffect(java.lang.String id,
                                             DataConverter dataConverter,
                                             Functions.Func1<java.util.Optional<byte[]>,java.util.Optional<byte[]>> func)

currentTimeMillis

long currentTimeMillis()

Returns:

time of the PollForDecisionTaskResponse start event of the decision being processed or replayed.

createTimer

java.util.function.Consumer<java.lang.Exception> createTimer(long delaySeconds,
                                                             java.util.function.Consumer<java.lang.Exception> callback)

Create a Value that becomes ready after the specified delay.

Parameters:

delaySeconds - time-interval after which the Value becomes ready in seconds.

callback - Callback that is called with null parameter after the specified delay. CancellationException is passed as a parameter in case of a cancellation.

Returns:

cancellation handle. Invoke Consumer.accept(Object) to cancel timer.

sideEffect

byte[] sideEffect(Functions.Func<byte[]> func)

Executes the provided function once, records its result into the workflow history. The recorded result on history will be returned without executing the provided function during replay. This guarantees the deterministic requirement for workflow as the exact same result will be returned in replay. Common use case is to run some short non-deterministic code in workflow, like getting random number or new UUID. The only way to fail SideEffect is to throw Error which causes decision task failure. The decision task after timeout is rescheduled and re-executed giving SideEffect another chance to succeed.

Parameters:

func - function that is called once to return a value.

Returns:

value of the side effect.

getVersion

int getVersion(java.lang.String changeID,
               DataConverter dataConverter,
               int minSupported,
               int maxSupported)

GetVersion is used to safely perform backwards incompatible changes to workflow definitions. It is not allowed to update workflow code while there are workflows running as it is going to break determinism. The solution is to have both old code that is used to replay existing workflows as well as the new one that is used when it is executed for the first time. GetVersion returns maxSupported version when executed for the first time. This version is recorded into the workflow history as a marker event. Even if maxSupported version is changed the version that was recorded is returned on replay. DefaultVersion constant contains version of code that wasn't versioned before.

Parameters:

changeID - identifier of a particular change

minSupported - min version supported for the change

maxSupported - max version supported for the change

Returns:

version

newRandom

java.util.Random newRandom()

getMetricsScope

com.uber.m3.tally.Scope getMetricsScope()

Returns:

scope to be used for metrics reporting.

getEnableLoggingInReplay

boolean getEnableLoggingInReplay()

Returns:

whether we do logging during decision replay.

randomUUID

java.util.UUID randomUUID()

Returns:

replay safe UUID